1. Field of the Invention
The present invention relates to a fuel tank structure that is provided in a vehicle such as an automobile or the like.
2. Description of the Related Art
As a fuel tank structure that is provided in a vehicle such as an automobile or the like, Japanese Patent Application Laid-Open (JP-A) No. 7-304340 discloses a structure in which a jet pump is provided at a first tank portion of a saddle-shaped fuel tank. In this structure, negative pressure is applied to the interior of the jet pump by fuel that is returned from an engine through a return pipe. Fuel is sent to the jet pump from a second tank portion due to the negative pressure.
However, in the fuel tank structure disclosed in JP-A No. 7-304340, because the discharge opening (exit pipe) of the fuel from the jet pump is positioned within fuel, there is resistance to the expelling of the fuel, and the fuel transferring ability of the jet pump is low.
In order to overcome such a drawback, it has been thought to place the jet pump above, and to position the fuel discharge opening above the liquid surface. However, when the fuel discharge opening of the jet pump is positioned above the liquid surface, air enters-in from the fuel discharge opening of the jet pump at times when fuel is no longer returned from the engine. Therefore, there is the concern that the phenomenon of the fuel within the return pipe or the like flowing-out (so-called fuel flow-out) will arise.
Further, in the structure of JP-A No. 7-304340, when, fuel from the engine is no longer returned in a state in which, for example, the liquid level of a first tank chamber is higher than the liquid level of a second tank chamber, there is the concern that, due to the difference in heights in the first tank chamber and the second tank chamber, the phenomenon will arise that the fuel in the first tank chamber flows backward to the second tank chamber through a transfer pipe (suction pipe).